Sharp EL-9900 - Manual (Page 58)

5
Advanced Keyboard/ALGEBRA USING THE SHARP EL-9900
Copyright © 2002, Sharp Electronics Corporation. Permission is granted to photocopy for educational use only.
Graphing a polynomial and zooming to find the roots
1. Turn the calculator on and press Y= . Y prompts will appear on the viewing
window. Press CL to remove old Y expressions. Setup the calculator with
rectangular coordinates and the equation editor mode by pressing 2ndF
SET UP E (COORD) 1 (Rect) G (EDITOR) and 1 (Equation). Press CL
to exit the menu and return to the Y prompts.
2. To enter the polynomial y = x 3 – 3x 2 + x + 1, press X/
θ/T/n a b 3
– 3 X/
θ/T/n x 2 + X/
θ/T/n + 1 .
3. Press ZOOM A (Zoom) 7 (Dec) to establish the decimal viewing window
and view the graph. Press TRACE to engage the trace feature. Press to
move the cursor near the left-hand root.
4. Set the zoom factors to 5 by pressing ZOOM B (FACTOR) press
ENTER 5 ENTER 5 ENTER . Press ZOOM A (ZOOM) 3 (In)
to zoom in on the left- hand root. Press TRACE and move the tracer to
approximate the root.
5. Press ZOOM H (RCL) 2 (PreWin) to return to the decimal viewing
window. Press TRACE and move the tracer to find the middle root.
6. Press repeatedly to move the tracer near the right-hand root. Press
ZOOM A (ZOOM) 3 (In) to zoom in. Press TRACE and move the tracer
to approximate the root.
GRAPHING POLYNOMIALS AND
FINDING THE ROOTS
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